Saturday, November 27, 2010

U.S.S. Atlantis – Steps 1 and 2, Engine Mount Assy

Steps 1 and 2 will focus on the engine mount assembly:


We will divert from the kit design just slightly here. The Estes design makes use of one adapter ring (part# AR-2050) at the nose end and a much thinner card stock adapter ring at the rear.
This may have been to save weight or more likely cost (punched card stock is much cheaper than the heavy paper tube the AR-2050 adapter rings are cut from).

If I decide to fly this model, stronger is better so we will make use of two AR-2050s to center the engine mount in the body tube, but we will save the cardstock version for a cosmetic cover in the next step. Notice that the cardstock rear adapter ring has a notch cut out of it for the engine hook. This is to allow the engine hook to move slightly to insert a motor. We will have to cut a similar notch in the AR-2050.


ADDITIONAL NOTE: Notice that Estes part numbers (e.g. AR-2050) tell you quite a bit about the part. The “AR” tells you what kind of part it is (Adapter Ring in this case) and the 2050 tells you that it is sized to adapt between a BT-20 body tube and a BT-50 body tube.

The second modification (improvement) we will make is the addition of an engine block above the retention hook inside the motor tube. This is just an added precaution and gives the head end of the motor a little more surface area to “push” against during the boost phase. This is another inexpensive piece of insurance and I will add these to any kit that relies solely on the hook to retain the motor in position during flight.


After glueing the thrust block and second adapter ring in place, we now we have our completed engine mount:


This completes steps 1 and 2 in the kit instructions and our engine mount is now ready to be installed in the main body tube. This is actually step 5 in the instructions as steps 3 and 4 deal with ataching the shock cord and shock cord mount in the main body tube. However, as described in an earlier post we will not be using the kit supplied shock cord. So we will come back to steps 3 and 4 in a later post. It is often easier to delay shock cord atachment until later in construction with smaller models where the shock cord is to be mounted to the inside of the main body tube.

ADDITIONAL NOTE: When I first built this kit back in 1977, I used good old Elmer’s glue for most of the construction. While that’s fine for smaller rockets that won’t have to endure massive boost forces, I think that there are better options out there. Some people like to use cyanacrylates (super glues) for just about everything but I find them unforgiving and prone to getting finger prints on the exterior parts of the model (maybe I’m just sloppy). So for construction of this kit, I have chosen to use two-part epoxy as my primary adhesive. It is slightly more cumbersome to use than other adhesives due to having to mix each batch as you go, but the fact that it cures in 5 minutes, is strong and ages well (not a lot of shrinkage or brittleness) makes it worth the extra effort in my opinion.


U.S.S. Atlantis - Parts Inventory and Inspection

Upon initial inspection all but one of the parts were present. The missing part was an adapter ring (part# AR-2050). These are fairly common and I was able to find one in my spare parts assortment. By the way that brings up a good point. ALWAYS save leftover parts. Model rocketry often involves modifying or repairing a model and having a good assortment of spare parts onhand can save alot time, expense, and trips to the hobby store.

Closer inspection of each individual part revealed a few more issues which wasn't surprising given the number of years I've been dragging this kit around. The main body tube (part# BT-50) had a pretty significant crease in it where something had been set on it. I was fortunate to also have a spare one of these in my parts assortment. The other damaged items were all in the recovery system. The parachute (part# PK-12A) had a pretty large slit cut in it (possibly from a hobby knife gone astray), there was a missing tape disc (part# TD-3F) and the rubber schock cord (part# SC-1) had hardened over the years and become brittle.
No big deal on the recovery system damage, as I was planning on upgrading to a nylon parachute kit with a Kevlar shock cord in any case, so these parts are not needed and can be discarded.
I was pleased that while there was some significant yellowing of the instructions and pattern sheet (part# SP-83) as can be seen in the above photo, the decal sheet (part# KD-83) was still pretty clean. Storing your kits out of direct sunlight will help to reduce yellowing. Unfortunately, this kit had sat on a shelf in my hobby room for the last couple of years and was exposed to direct sunlight through an open window. I must have lucked out that the decal sheet was tucked in behind something and didn't get as much exposure.
Well thats about it for the parts inventory and inspection. In our next post we will begin construction!

Thursday, November 25, 2010

Estes Classic Kit Build - U.S.S. Atlantis

Well I'm gonna finally dust off the old workbench this weekend and since it's been quite awhile since I started this blog I have apologize to my single follower out there (sorry Jeff) that I've been so lax in getting anything built. Actually that's not exactly true as I've done several model railroading projects recently but that's not the subject of this blog... This is a spacemodeling blog so let's build some rockets!

For my inagural spacemodeling project, I've decided to go ahead and build one of my absolute favorite old Estes kits from the 1970's... The "USS Atlantis" (kit# 1283). This kit was introduced in 1976 as something that might have existed in the "Star Trek" universe. I bought several of these kits back in the 1980s from Earl's Hobby Shop in Bellflower, CA (a favorite So Cal rocketry hang out back in the day) with the thought that I would build at least one while saving the others as collectors kits. This is the only one I managed to hang onto and since it got opened somewhere along the way, whats the harm in building it. This should be fun and will hopefully bring back some fond old memories of the last time I built one of these back in the mid-1970s.




The first thing we'll do is inventory our parts and check on their condition. After all the kit is over 30 years old...